Underfill material dispensing for stacked semiconductor chips

ABSTRACT

A template having tapered openings can be employed to enable injection of underfill material through gaps having a width less than a lateral dimension of an injector needle for the underfill material. Each tapered opening has a first lateral dimension on an upper side and a second lateral dimension on a lower side. Compliant material portions can be employed to accommodate variations in distance between the template and stacked semiconductor chips and/or an injector head. Optionally, another head can be employed to apply compressed gas to push out the underfill material after the underfill material is applied to the gaps. Multiple injector heads can be employed to simultaneously inject the underfill material at different sites. An adhesive layer can be substituted for the at least one lower compliant material portion.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.13/567,567, filed Aug. 6, 2012, which is a continuation of U.S. patentapplication Ser. No. 13/549,848, filed Jul. 16, 2012 the entire contentand disclosure of which are incorporated herein by reference.

BACKGROUND

The present disclosure relates to methods of dispensing underfillmaterial for stacked semiconductor chips, and structures for effectingthe same.

In three-dimensional stacked structures including a plurality ofsemiconductor chips attached to a substrate, it is preferred that thegap among the plurality of semiconductor chips be as small as possiblein order to minimize unused area of the substrate. The substrate can bea interposer substrate or a packaging substrate. Reduction of the gapbetween neighboring semiconductor chips increases the percentage of thearea of the substrate that is used for stacking semiconductor chips, andthus, reduces manufacturing cost.

As the width of the gap decreases, however, it becomes difficult to fillthe gap with the underfill material through underfill dispensing methodsknown in the art. Particularly, when the gap becomes smaller than thediameter of a needle of an underfill dispenser, the needle cannot beinserted into the gap for effective dispensing of the underfillmaterial.

SUMMARY

A template having tapered openings can be employed to enable injectionof underfill material through gaps having a width less than a lateraldimension of an injector needle for the underfill material. Each taperedopening has a first lateral dimension on an upper side and a secondlateral dimension on a lower side. At least one lower compliant materialportion can be employed to accommodate variations in distance betweenthe template and stacked semiconductor chips bonded to a substrate, andan upper compliant material portion can be employed to seal an injectorhead against top surfaces of the stacked semiconductor chips.Optionally, another head can be employed to apply compressed gas to pushout the underfill material after the underfill material is applied tothe gaps. Multiple injector heads can be employed to simultaneouslyinject the underfill material at different sites. An adhesive layer canbe substituted for the at least one lower compliant material portion.

According to an aspect of the present disclosure, a method of processinga bonded structure is provided. A template is disposed over a pluralityof semiconductor chips in a bonded structure. The plurality ofsemiconductor chips is bonded to a substrate within the bondedstructure. The template includes a plurality of template openingsextending between a proximal surface and a distal surface of thetemplate. Each of the plurality of template openings has a first lateraldimension at the proximal surface and has a second lateral dimensionthat is greater than the first dimension at the distal surface. Thedistal surface is more distal from the bonded structure than theproximal surface. An injector head is disposed over a template openingamong the plurality of template openings. An underfill material isdispensed from the injector head, through the template opening, and intoa gap within the bonded structure.

According to another aspect of the present disclosure, a structureincludes a bonded structure, which includes a plurality of semiconductorchips bonded to a substrate. The structure further includes a templatedisposed over the bonded structure. The template includes a plurality oftemplate openings extending between a proximal surface and a distalsurface of the template. Each of the plurality of template openings hasa first lateral dimension at the proximal surface and has a secondlateral dimension that is greater than the first dimension at the distalsurface. The distal surface is more distal from the bonded structurethan the proximal surface.

According to yet another aspect of the present disclosure, a structureincludes at least a template. The template includes a plurality oftemplate openings extending between a first surface and a second surfaceof the template. Each of the plurality of template openings has a firstlateral dimension at the first surface and has a second lateraldimension that is greater than the first dimension at the secondsurface. The plurality of template openings is a two-dimensionalperiodic array of openings having a periodicity in two horizontaldirections.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a vertical cross-sectional view of a first exemplary structureincluding a plurality of semiconductor chips bonded to a substrate, atemplate, a lower compliant material layer, an upper compliant materialportion, and an injector head according to a first embodiment of thepresent disclosure.

FIG. 2 is a vertical cross-sectional view of the first exemplarystructure during injection of an underfill material according to thefirst embodiment of the present disclosure.

FIG. 3 is a vertical cross-sectional view of a variation of the firstexemplary structure during injection of an underfill material accordingto the first embodiment of the present disclosure.

FIG. 4 is a vertical cross-sectional view of a second exemplarystructure including a plurality of semiconductor chips bonded to asubstrate, a template, a lower compliant material layer, an uppercompliant material portion, an injector head, and compressed gasdispenser according to a second embodiment of the present disclosure.

FIG. 5 is a vertical cross-sectional view of a third exemplary structureincluding a plurality of injector heads according to a third embodimentof the present disclosure.

FIG. 6 is a variation of the third exemplary structure during injectionof an underfill material according to the third embodiment of thepresent disclosure.

FIG. 7 is a vertical cross-sectional view of a fourth exemplarystructure including a template according to a fourth embodiment of thepresent disclosure.

FIG. 8 is a vertical cross-sectional view of the fourth exemplarystructure after application of an adhesive layer according to the fourthembodiment of the present disclosure.

FIG. 9 is a vertical cross-sectional view of the fourth exemplarystructure after formation of holes through the adhesive layer accordingto the fourth embodiment of the present disclosure.

FIG. 10 is a vertical cross-sectional view of the fourth exemplarystructure after attaching the adhesive layer to a stack of semiconductorchips bonded to a substrate according to the fourth embodiment of thepresent disclosure.

FIG. 11 is a vertical cross-sectional view of the fourth exemplarystructure after placing an injector head on the template through anupper compliant material portion according to the fourth embodiment ofthe present disclosure.

FIG. 12 is a vertical cross-sectional view of the fourth exemplarystructure after application and curing of the underfill materialaccording to the fourth embodiment of the present disclosure.

FIG. 13 is a vertical cross-sectional view of the fourth exemplarystructure after removal of a handle substrate and formation of backsidestructures on the substrate according to the fourth embodiment of thepresent disclosure.

FIG. 14 is a vertical cross-sectional view of the fourth exemplarystructure after detaching the template according to the fourthembodiment of the present disclosure.

FIG. 15 is a vertical cross-sectional view of the fourth exemplarystructure after dicing according to the fourth embodiment of the presentdisclosure.

FIG. 16 is a vertical cross-sectional view of a fifth exemplarystructure including a plurality of semiconductor chips bonded to asubstrate, a template, an adhesive layer, an upper compliant materialportion, an injector head, and compressed gas dispenser according to afifth embodiment of the present disclosure.

FIG. 17 is a vertical cross-sectional view of a third exemplarystructure including a plurality of injector heads according to a sixthembodiment of the present disclosure.

FIG. 18 is a top-down view of a first exemplary template according to anembodiment of the present disclosure.

FIG. 19 is a top-down view of a second exemplary template according toan embodiment of the present disclosure.

FIG. 20 is a top-down view of a third exemplary template according to anembodiment of the present disclosure.

FIG. 21 is a top-down view of an exemplary compliant material layeraccording to an embodiment of the present disclosure.

DETAILED DESCRIPTION

As stated above, the present disclosure relates to methods of dispensingunderfill material for stacked semiconductor chips, and structures foreffecting the same, which are now described in detail with accompanyingfigures. It is noted that like and corresponding elements are referredto by like reference numerals. The drawings are not drawn to scale.

Referring to FIG. 1, a first exemplary structure according to a firstembodiment of the present disclosure includes a bonded structure, whichincludes at least a substrate 100 and a plurality of semiconductor chips200. The plurality of semiconductor chips 200 is bonded to the substrate100 either directly through solder balls 180 or indirectly through atleast one intervening semiconductor chip and at least two arrays ofsolder balls 180 located at different levels. The substrate 100 can be ainterposer substrate with through-substrate vias (TSVs), a semiconductorsubstrate, or a packaging substrate as known in the art. The lateralextent of the substrate 100 is selected such solder balls 180 bondeddirectly to the substrate 100 are also directly bonded to at least twosemiconductor chips among the plurality of semiconductor chips 200. Thesolder balls 180 can be Controlled Collapse Chip Connect (C4) balls asknown in the art.

Optionally, the bonded structure can further include a handle substrate10 and an intermediate bonding layer 20. In addition the bondedstructure may further include an intermediate bonding layer 20. Thesubstrate 100 can be bonded to the handle substrate 10 directly, orthrough the intermediate bonding layer 20, which can be, for example, anadhesive layer. The handle substrate 10 can be a semiconductorsubstrate, an insulator substrate, a conductive substrate, or acombination thereof. The handle substrate 10 can provide mechanicalsupport to the substrate 100 during subsequent handling of the bondedstructure (100, 180, 200, 10, 20).

The plurality of semiconductor chips 200 is grouped into subsets ofsemiconductor chips 200 such that each subset occupies a same area.Thus, if a subset of semiconductor chips 200 includes multiplesemiconductor chips 200, all semiconductor chips 200 within the samesubset overlie or underlie one another. Prior to being bonded to thesubstrate 100, the subsets of semiconductor chips 200 are arranged overthe substrate 100 such that each subset of semiconductor chips 200 islaterally spaced from neighboring subsets of semiconductor chips 200 bya lateral spacing. The lateral spacing is of the lateral gap betweeneach pair of neighboring subsets of semiconductor chips 200 can be from0.1 mm to 3 mm, although lesser and greater lateral spacings can also beemployed.

A compliant material layer 320 is disposed on the top surfaces of theplurality of semiconductor chips 200. The compliant material layer 320includes a compliant material, which is an elastic material, i.e., amaterial that recovers an original shape after deformation once theforce that introduces the deformation is removed. In one embodiment, thecompliant material layer 320 can include a material having Young'smodulus less than 1.0 GPa, which can be, for example, rubber, silicone,or polytetrafluoroethylene. In another embodiment, the compliantmaterial layer 320 can include a material having Young's modulus lessthan 0.2 GPa, which can be, for example, rubber. The thickness of thecompliant material layer 320 can be, for example, from 0.5 mm to 1 cm,although lesser and greater thicknesses can also be employed.

The compliant material layer 320 includes at least one compliantmaterial portion, which is herein referred to as at least one lowercompliant material portion. The compliant material layer 320 can be asingle layer including a plurality of holes, or a collection ofdisjoined lower compliant material portions.

The openings in the compliant material layer 320 include openings thatoverlie the spaces between neighboring pair of subsets of semiconductorchips 200, i.e., openings that overlie the lateral spacings. Theopenings in the compliant material layer 320 are herein referred to ascompliant material openings 319. In one embodiment, each compliantmaterial opening 319 can be wider than an underlying lateral spacing. Inone embodiment, the plurality of compliant material openings 319 canhave a lateral dimension ld that is greater than the lateral spacing isamong the plurality of semiconductor chips 200.

For example, the width of the openings in the compliant material layer320 can be, for example, from 1 mm to 2 cm, although lesser and greaterwidths can also be employed. In one embodiment, the compliant materiallayer 320 can include a plurality of compliant material openings 319that overlie lateral gaps among the plurality of semiconductor chips200. In one embodiment, each overlying compliant material opening 319can overlap the entirety of the area of the underlying lateral gapbetween a neighboring pair of subsets of semiconductor chips 200.

A template 310 is disposed on an upper surface of the compliant materiallayer 320. The template 310 includes a rigid material, which can be, forexample, a semiconductor material, an insulator material, or aconductive material. For example, the template 310 can include silicon,glass, a ceramic material, a metallic material, or a combinationthereof. The thickness of the compliant material layer 320 can be from 1mm to 2 cm, although lesser and greater thicknesses can also beemployed. In one embodiment, the plurality of template openings canoverlie the plurality of compliant material openings 319 upon disposingof the template 310 on the compliant material layer 320.

The template 310 includes a plurality of template openings 309. Each ofthe plurality of template openings 309 extends from a horizontal surfacethat is proximal to the bonded structure (10, 20, 100, 180, 200) to ahorizontal surface that is distal from the bonded structure (10, 20,100, 180, 200). The horizontal surface of the template 310 that isproximal to the bonded structure (10, 20, 100, 180, 200) is hereinreferred to as a proximal surface, and the horizontal surface of thetemplate 310 that is distal from the bonded structure (10, 20, 100, 180,200) is herein referred to as a distal surface. Thus, the distal surfaceis more distal from the bonded structure (10, 20, 100, 180, 200) thanthe proximal surface. Each of the plurality of template openings 309 hasa first lateral dimension ld1 at the proximal surface, and has a secondlateral dimension ld2 that is greater than the first lateral dimensionld1 at the distal surface.

In one embodiment, each of the plurality of template openings 309 canhave a non-zero taper angle α relative to the surface normal of thedistal surface between the distal surface and the proximal surface. Thenon-zero taper angle α can have a value between, and excluding, 0 degreeand 90 degrees. In one embodiment, the non-zero taper angle α can have avalue between, and including, 10 degrees and 80 degrees. In oneembodiment, the non-zero taper angle α can have a value between, andincluding, 20 degrees and 70 degrees. In one embodiment, the non-zerotaper angle α can have a value between, and including, 30 degrees and 60degrees. In one embodiment, each of the plurality of template openings309 can overlie one of the plurality of compliant material openings 319.

The compliant material layer 320 and the template 310 can be provided astwo separate structures that are disposed separately on the bondedstructure (10, 20, 100, 180, 200), or can be provided as a pre-assembledstructure that is attached to each other, either temporarily orpermanently, prior to placing on the top surface of the plurality ofsemiconductor chips 200. The assembly of the compliant material layer320 and the template 310 is herein referred to as a template assembly300. The plurality of template openings 309 can be a two-dimensionalperiodic array of openings having a periodicity in two horizontaldirections. The plurality of compliant material openings 319 can havethe same periodicity in the two horizontal directions as the pluralityof template openings 309.

Each of the plurality of template openings 309 extends between a firstsurface, i.e., the proximal surface, and a second surface, i.e., thedistal surface. Each of the plurality of template openings 309 can havea first lateral dimension ld1 at the first surface, and can have asecond lateral dimension ld2 that is greater than the first lateraldimension ld2 at the second surface. The plurality of template openings309 can be a two-dimensional periodic array of openings having aperiodicity in two horizontal directions.

An injector head 400 can be provided over the template assembly 300. Theinjector head 400 can include an injector tip 420 and an injectormanifold 410 configured to hold an underfill material prior toinjection. The injector head 400 is configured to extrude, i.e., inject,the underfill material from the injector manifold 410 through theinjector head 420 into the space underlying the injector head 420. Theunderfill material can be any underfill material as known in the art.

In one embodiment, the lateral dimension of an opening in the injectortip 420 can be greater than the lateral spacing is among the pluralityof semiconductor chips 200. In one embodiment, the opening of theinjector tip 420 can have a circular cross-sectional area, and thelateral dimension of the opening in the injector tip 420 can be theinner diameter of the injector tip 420.

The injector head 400 is disposed over a template opening among theplurality of template openings 309. Optionally, a compliant materialportion 430 can be disposed between the template 310 and the injectorhead 400. The compliant material portion 430 can provide a seal betweenthe template 310 and the injector head 400. The compliant materialportion 430 includes a compliant material, i.e., an elastic material. Inone embodiment, the compliant material portion 430 can include amaterial having Young's modulus less than 1.0 GPa, which can be, forexample, rubber or polytetrafluoroethylene. In another embodiment, thecompliant material portion 430 can include a material having Young'smodulus less than 0.2 GPa, which can be, for example, rubber. Thethickness of the compliant material portion 430 can be, for example,from 0.5 mm to 1 cm, although lesser and greater thicknesses can also beemployed. In one embodiment, the compliant material portion 430 can bepermanently affixed to a face of the injector head 400 that is proximalto the template 310. In one embodiment, the compliant material portion430 can be ring-shaped, and can contact a periphery of a proximal faceof the injector head 400 from which the injector top 420 protrudes.

Referring to FIG. 2, the underfill material 40 can be dispensed whilethe compliant material portion 430 provides a seal between the template310 and the injector head 400 and the compliant material layer 320provides another seal between the template 310 and the plurality ofsemiconductor chips 200. The underfill material 40 is dispensed from theinjector head 400, through the template opening 309 that underlies theinjector head 400, and into a lateral gap within the bonded structure(10, 20, 100, 180, 200). The underfill material 40 flows throughinterface between the compliant material opening underneath the injectorhead 400 and the lateral gap underneath the compliant material opening,and flows into the various cavities among the plurality of semiconductorchips 200 in the vicinity of the interface. The underfill materialextends at least from the template opening 309 and fills at least onelateral gap and at least one vertical gap within the bonded structure(10, 20, 100, 180, 200).

In one embodiment, the injector head 400 can apply pressure to theunderfill material so as to facilitate the flow of the underfillmaterial through the various cavities among the plurality ofsemiconductor chips 200. In one embodiment, vacuum environment may beemployed to facilitate the flow of the underfill material.

In one embodiment, the lateral dimension of the opening in the injectortip 420 can be greater than the lateral dimension is of the lateral gapsbetween neighboring pairs of semiconductor chips 200 because theinjector tip 420 does not need to be inserted into any of the lateralgaps.

The injector head 400 and the compliant material portion 430 can bemoved from one compliant material opening 309 to other compliantmaterial openings 309 until the underfill material 40 fills all of thecavities among the plurality of semiconductor chips 200. Subsequently,the injector head 400, the compliant material portion 430, and thetemplate assembly 300 can be removed from above the bonded structure(10, 20, 100, 180, 200, 40), which includes the underfill material 40.

Referring to FIG. 3, a variation of the first exemplary structure can bederived from the first exemplary structure by bonding all of theplurality of semiconductor chips 200 directly to the substrate 100through an array of solder balls 180 instead of forming a plurality ofvertical stacks of two or more semiconductor chips 200.

Referring to FIG. 4, a second exemplary structure according to a secondembodiment of the present disclosure can be derived from the firstexemplary structure by adding a gas dispenser 500. Once the underfillmaterial 40 is applied by the injector head 400 through a firstcompliant material opening 309, the injector head 400 can be moved anddisposed over a second compliant material opening to inject additionalunderfill material 40. The gas dispenser 500 is placed over the firstcompliant material opening 309 after the underfill material is dispensedthough the lateral gap underlying the first compliant material opening309.

In one embodiment, the gas dispenser 500 can include a gas injector tip520 or a gas injection opening located on a proximal face of a gasinjection manifold 510. A compliant material portion, which is hereinreferred to as a gas-dispenser compliant material portion 530, can bedisposed between the template 310 and the gas dispenser 500 to provide aseal between the gas dispenser 500 and the template 310. The gas flowsthrough the gas dispenser 500, and is dispensed by the gas dispenser 500into a cavity 50 confined by the gas dispenser 500, the gas-dispensercompliant material portion 530, the template 310, a top surface of theunderfill material 40, and optionally the compliant material layer 320.The cavity 50 is filled with a pressurized gas, which is at a higherpressure relative to the pressure of the ambient in which the secondexemplary structure is placed. In one embodiment, the pressure of thegas within the cavity 50 can be adjusted so that the top surface of theunderfill material 40 underlying the cavity 50 is between a horizontalplane of a bottom surface of semiconductor chips 200 located at thetopmost layer of semiconductor chips 200 and a horizontal planeincluding a top surface of the compliant material layer 320.

The gas dispenser 500 and the gas-dispenser compliant material portion530 can be moved from one compliant material opening 309 to othercompliant material openings 309 until the top surfaces of the underfillmaterial 40 are placed between a horizontal plane of a bottom surface ofsemiconductor chips 200 located at the topmost layer of semiconductorchips 200 and a horizontal plane including a top surface of thecompliant material layer 320. Subsequently, the injector head 400, thecompliant material portion 430, the gas dispenser 500, the gas-dispensercompliant material portion 530, and the template assembly 300 can beremoved from above the bonded structure (10, 20, 100, 180, 200, 40),which includes the underfill material 40.

Referring to FIG. 5, a third exemplary structure according to a thirdembodiment of the present disclosure can be derived from the firstexemplary structure by substituting a plurality of injector heads 400and a plurality of compliant material portions 430 for the combinationof a single injector head 400 and a single compliant material portion430. The plurality of injector heads 400 can be disposed over theplurality of template openings 309 (See FIG. 1) after placement of theplurality of compliant material portions 430 on the top surface of thetemplate 310. The underfill material 40 can be simultaneously orsequentially dispensed from the plurality of injector heads 400, throughthe plurality of template openings 309, and into the lateral gaps amongthe plurality of semiconductor chips 200 within the bonded structure(10, 20, 100, 180, 200).

In one embodiment, the simultaneous or sequential dispensation of theunderfill material 40 from the plurality of injector heads 400 can becontrolled by a dispensing controller 700, which can include a computerand a communication interface system for controlling the injection ofthe underfill material through the injector manifolds 410. In oneembodiment, an underfill material supply system can be provide, whichcan include, for example, an underfill material reservoir 550 that holdsthe underfill material 40 and underfill material transfer tubes 560through which the underfill material 40 is transferred from theunderfill material reservoir 550 to the injection manifolds 410. In oneembodiment, the dispensing controller 700 can be configured to cause theinjector heads 400 to simultaneously inject the underfill material 40.In another embodiment, the dispensing controller 700 can be configuredto cause the injector heads 420 to sequentially inject the underfillmaterial.

Referring to FIG. 6, a variation of the third exemplary structure can bederived from the third exemplary structure by bonding all of theplurality of semiconductor chips 200 directly to the substrate 100through an array of solder balls 180 instead of forming a plurality ofvertical stacks of two or more semiconductor chips 200.

Referring to FIG. 7, a fourth exemplary structure according to a fourthembodiment of the present disclosure includes a template 310, which canbe the same as the template 310 of the first, second, and thirdembodiments. The template 310 includes a plurality of template openings309 extending between a first surface and a second surface. Each of theplurality of template openings 309 has a first lateral dimension ld1 atthe first surface, and has a second lateral dimension ld2 that isgreater than the first lateral dimension ld1 at the second surface. Theplurality of template openings 309 can be a two-dimensional periodicarray of openings having a periodicity in two horizontal directions. Thetemplate 310 can be provided as a stand-alone piece.

Referring to FIG. 8, an adhesive layer 1320 is applied to first surfaceof the template 310. The adhesive layer 1320 can include any materialthat can provide adhesion to the template 310 and top surfaces ofsemiconductor chips to be subsequently attached to the adhesive layer1320. In one embodiment, the adhesive layer 1320 can include anepoxy-based adhesive material. The thickness of the adhesive layer 1320can be from 10 micron to 1 mm, although lesser and greater thicknessescan also be employed.

Referring to FIG. 9, holes are formed through the adhesive layer 1320,for example, by employing at least one pointy mechanical structure,which can be, for example, one or more needles. In one embodiment, aplate including an array of needles can be employed to form the holesthrough the adhesive layer 1320. The openings in the adhesive layer 1320are herein referred to as a plurality of adhesive layer openings. Theplurality of adhesive layer openings overlies or underlies the pluralityof template openings 309. In one embodiment, the first lateral dimensionld1 of the compliant material opening 319 can be greater than a lateraldimension ld′ of the adhesive layer openings. In one embodiment, thelateral dimension of the adhesive layer openings can be the diameter ofthe hole. In one embodiment, the plurality of adhesive layer openingscan have a lateral dimension ld′ that is less than first lateraldimension ld1. For example, the lateral dimension ld′ of the adhesivelayer openings can be, for example, from 1 mm to 2 cm, although lesserand greater widths can also be employed.

Referring to FIG. 10, the template 310 and the adhesive layer 1320 arealigned relative to a plurality of semiconductor chips 200 within abonded structure (10, 20, 100, 180, 200). The bonded structure (10, 20,100, 180, 200) can be the same as in the first, second, or thirdembodiments. The adhesive layer 1320 is subsequently attached to thebonded structure (100, 180, 200, 10, 20) that includes vertical stacksof semiconductor chips 200 and the substrate 100. The combination of thetemplate 310 and the adhesive layer 1320 is aligned such that theplurality of adhesive layer openings overlies lateral gaps among theplurality of semiconductor chips 200 upon disposition, i.e., placement,of the template layer 310 over the plurality of semiconductor chips 200.Upon placement of the combination of the template 310 and the adhesivelayer 1320 on the bonded structure (10, 20, 100, 180, 200), the adhesivelayer 1320 contacts the topmost surfaces of the plurality ofsemiconductor chips 200.

The plurality of adhesive layer openings underlies the plurality oftemplate openings 309. In one embodiment, the adhesive layer 1320 caninclude a plurality of adhesive layer openings that overlie lateral gapsamong the plurality of semiconductor chips 200. In one embodiment, eachof the adhesive layer openings can have a lateral dimension ld′ (SeeFIG. 9) that is less than the first lateral dimension ld1 (See FIG. 7).In one embodiment, each overlying adhesive material opening can overlapthe entirety of the area of the underlying lateral gap between aneighboring pair of subsets of semiconductor chips 200.

Referring to FIG. 11, an injector head 400 and a compliant materialportion 430 are placed over the template 310 in the same manner as inthe first embodiment as illustrated in FIG. 1.

Referring to FIG. 12, the processing steps of FIG. 2 are performed todispense the underfill material 40. The compliant material portion 430and the injector head 400 are subsequently removed. The underfillmaterial can be cured at an elevated temperature as needed.

Referring to FIG. 13, the handle substrate 10 and the intermediatebonding layer 20 can be removed. The removal of the handle substrate 10and the intermediate bonding layer 20 can be effected, for example, bydetachment, grinding, etch, planarization, or combinations thereof.Patterned backside contact structures 80 can be formed on a surface ofthe substrate 100 that is physically exposed after the removal of thehandle substrate 10, i.e., on the back side surface of the substrate100. The patterned backside contact structures 80 can include, forexample, bonding pads for a ball grid array (BGA), which can be employedto subsequently bond diced portions of the substrate 100 to a packagingsubstrate.

Referring to FIG. 14, the template 310 can be detached from the adhesivelayer 1320, for example, by a wet etch that etches the adhesive layer1320 at least until the template is detached from the remaining portionsof the adhesive layer 1320. If the adhesive layer 1320 includes anepoxy-based material, an organic solvent can be employed to selectivelydissolve portions of the adhesive layer 1320 while not etching thesemiconductor chips 200.

Referring to FIG. 15, the fourth exemplary structure including thesubstrate 100, the plurality of semiconductor chips 200, and thedispensed underfill material 40 are diced by cutting through portions ofthe dispensed underfill material 40 within the fourth exemplarystructure. In one embodiment, each diced structure of the fourthexemplary structure can include a diced interposer unit 100′, a subsetof the plurality of semiconductor chips 200 that are vertically stackedthereupon, arrays of solder balls 180 that provide verticalinterconnections within the subset, and the underfill material 40, whichcan compensate for the mismatch in thermal expansion coefficients ofdifferent materials. Each diced portion of the fourth exemplarystructure can be mounted, for example, on a packaging substrate (notshown) as known in the art.

Further, while the dicing operation is illustrated only for the fourthexemplary structure, any of the exemplary structures of the presentdisclosure can be diced to provide the diced structures illustrated inFIG. 15.

Referring to FIG. 16, a fifth exemplary structure according to a fifthembodiment of the present disclosure can be derived from the fourthexemplary structure of FIG. 11 by employing the components of the secondembodiment as described above. Specifically, a gas dispenser 500 and agas-dispenser compliant material portion 530 can be added and operatedas in the second embodiment.

Referring to FIG. 17, a sixth exemplary structure according to a sixthembodiment of the present disclosure can be derived from the fourthexemplary structure by substituting a plurality of injector heads 400and a plurality of compliant material portions 430 for the combinationof a single injector head 400 and a single compliant material portion430 in the same manner as in the third embodiment. The plurality ofinjector heads 400, a dispensing controller 700, an underfill materialreservoir 550, and underfill material transfer tubes 560 can be operatedin the same manner as in the third embodiment.

Referring to FIG. 18, a template 310 according to an embodiment of thepresent disclosure includes a plurality of template openings 309, whichis provided as a two-dimensional periodic array of openings having aperiodicity in two horizontal directions. The width of each templateopenings 309 correspond to the first lateral dimension ld1. Thelocations of the plurality of semiconductor chips 200 are schematicallyillustrated with dotted lines, which do not correspond to the sidewallsof the semiconductor chips 200. In one embodiment, the plurality oftemplate openings 309 may be located only at one corner of eachsemiconductor chip 200. Because the underfill material 40 can flowthrough the various vertical and lateral gaps among the semiconductorchips 200, it is not necessary to form the template openings 309 aroundthe entire periphery of each topmost semiconductor chip 200.

Referring to FIG. 19, a template 310 according to another embodiment ofthe present disclosure is illustrated. A plurality of template openings309 is provided as a two-dimensional periodic array of openings having aperiodicity in two horizontal directions. The width of each templateopenings 309 correspond to the first lateral dimension ld1. Thelocations of the plurality of semiconductor chips 200 are schematicallyillustrated with dotted lines, which do not correspond to the sidewallsof the semiconductor chips 200. The plurality of template openings 309may be located only at one side of each semiconductor chip 200.

Referring to FIG. 20, a template 310 according to yet another embodimentof the present disclosure is illustrated. A plurality of templateopenings 309 is provided as a two-dimensional periodic array of openingshaving a periodicity in two horizontal directions. The width of eachtemplate openings 309 correspond to the first lateral dimension ld1. Theplurality of template openings 309 may be located at each corner and ateach side of the topmost semiconductor chips 200 provided that thetemplate 310 can remain an integral structure, i.e., a single contiguousstructure.

Referring to FIG. 21, a compliant material layer 320 that can beemployed in conjunction with a template 310 of FIG. 18, 19, or 20 isillustrated. The compliant material layer 320 can have compliantmaterial openings 319 that overlie the lateral gaps among thesemiconductor chips 200 that can be disposed underneath.

The plurality of semiconductor chips 200 can be arranged with higherdensity in the configurations of the present disclosure compared toprior art configurations that require injector tips to be inserted intolateral gaps below the topmost surface of the plurality of semiconductorchips 200. Thus, the methods of the present disclosure can reduce theproduction cost for the process of bonding semiconductor chips 200 to aninterposer substrate or other types of substrates.

While the disclosure has been described in terms of specificembodiments, it is evident in view of the foregoing description thatnumerous alternatives, modifications and variations will be apparent tothose skilled in the art. Each of the various embodiments of the presentdisclosure can be implemented alone, or in combination with any otherembodiments of the present disclosure unless expressly disclosedotherwise or otherwise impossible as would be known to one of ordinaryskill in the art. Accordingly, the disclosure is intended to encompassall such alternatives, modifications and variations which fall withinthe scope and spirit of the disclosure and the following claims.

What is claimed is:
 1. A structure comprising at least a template, saidtemplate including a plurality of template openings extending between afirst surface and a second surface of said template, wherein each ofsaid plurality of template openings has a first lateral dimension atsaid first surface and has a second lateral dimension that is greaterthan said first lateral dimension at said second surface, wherein saidplurality of template openings is a two-dimensional periodic array ofopenings having a periodicity in two horizontal directions.
 2. Thestructure of claim 1, wherein each of said plurality of templateopenings has a non-zero taper angle relative to a surface normal of adistal surface of said template that is selected said first surface andsaid second surface.
 3. The structure of claim 1, further comprising acompliant material layer including at least one lower compliant materialportion and disposed directly on said template.
 4. The structure ofclaim 3, wherein said compliant material layer includes a plurality ofcompliant material openings that underlies said plurality of templateopenings.
 5. The structure of claim 1, further comprising an adhesivelayer disposed directly on said template layer.
 6. The structure ofclaim 5, wherein said adhesive layer comprises a plurality of adhesivelayer openings that underlie said plurality of template openings.
 7. Thestructure of claim 6, wherein each of said adhesive layer openings has alateral dimension that is less than said first lateral dimension.